Structures in civil, aerospace, marine or automotive engineering such as bridges, aircraft, spacecraft, ships or motor vehicles are engineered to perform under predetermined conditions such as an acceptable range of operational loading of elements of their structure. If elements of the structure are overloaded the structure may need to be replaced or repaired. Since such structures are engineered to perform under a certain degree of overloading without failure, any damage or degradation caused by such overloading may not be straightforwardly identifiable. For example, the landing gear of aircraft are designed to cope with heavy landings. However, some heavy landings may results in damage in the landing gear and aircraft structure that requires repair or replacement of aircraft parts.
One solution for detecting overloading in a structure is to model the situation in which damage is thought to have occurred and to calculate the stresses on the structure and from those calculations determine whether or not any repairs or part replacements are required. In another solution, strain gauges are located on the structure and used to measure the loadings. These measurements are then used to determine whether any overloading is of a level indicating that repair or part replacement is required. One problem with these techniques is that they are highly complex processes that require significant amounts of highly skilled manpower and equipment. Thus these processes are expensive, require significant maintenance and can incur significant down time for the structure being analysed.